The invention relates to wireless system communications. More particularly, the invention relates to the reduction of the set-up time for remote units utilizing packet data as opposed to switched data to communicate with a base station.
The wireless industry has grown at a tremendous pace over the past few years. Wireless communication has become a standard part of every day life. Most people utilize some derivative form of wireless communications such as Global System for Mobile communication (GSM), Universal Mobile Telecommunications System (UMTS), Carrier Detection Multiple Access (CDMA) and 802.11 in various aspects of daily living.
Generally, radio systems are designed for a certain area of coverage or footprint. These areas are generally referred to as cells. Cells enable the reuse of similar frequencies by multiple sources to support services in metropolitan areas that are some distance apart. The geographic size of cells are not necessarily consistent throughout a given area and may vary due to frequency and power level, topography of the area, time of day and so forth. Communications within these cells take advantage of a concept known as Demand Assigned Multiple Access (DAMA). DAMA enables multiple devices to access a network in a shared manner on a demand basis. Basically, devices access the network on a first come, first serve basis. Within a wireless network, there are a number of ways in which multiple access can be provided to end-users. At the most basic level, there is a Frequency Division Multiple Access (FDMA) methodology, which is essentially the starting point for all wireless communications, given that each cell must be separated by frequencies to avoid interferences among wireless devices. FDMA divides assigned frequency ranges into multiple carrier frequencies in order to support multiple conversations.
Another method that is utilized in wireless networking is the Time Division Multiple Access (TDMA), which is a digital technique that divides each frequency channel into multiple time slots. Each of the time slots within a frequency channel supports an individual device conversation. Generally speaking, services based on TDMA offer roughly three times the traffic capacity of FDMA services.
Yet another communication methodology, which is relatively new and has its root in spread spectrum radio is known as Code Division Multiple Access (CDMA). Spread spectrum radio spreads the bandwidth of a transmitted signal over a spectrum of radio frequencies. The combined spectrum of radio frequencies is usually much wider than what is required to support the narrow band transmission of the signal. Spread spectrum uses two techniques namely, Direct Sequence (DS) and Frequency Hopping (FH). In brief, direct sequence spread spectrum is a packet radio technique in which the narrow band signal is spread across a wider carrier frequency band. In other words, the signal information is organized into packets, each of which is transmitted across a wider carrier band frequency in a redundant manner i.e. packets are sent more than once. Multiple transmissions can then be supported. The transmissions from specific terminals are identified by a unique code such as, a 10 bit code that is pre-pended to each data packet. Frequency Hopping Spread Spectrum is generally preferred over direct sequence spread spectrum. FHSS involves transmission of short bursts of packets within the wide band carrier over a range of frequencies. Essentially, the transmitter and receiver hop from one frequency to another in a choreographed hop sequence and a number of packets are sent to each frequency. The hop sequence is controlled by a centralized base station antennae.
Regardless of the communication methodology for a given network, a certain amount of pre-configured set-up and real time set-up of communication devices will be required. One such requirement for communication between a remote/mobile unit and a base station is the set-up and configuration of certain communication parameters. For example, with packet data mode communications data rate, availability and maximum delay time for each packet communication must be set-up and negotiated between the remote unit and the base. Generally, this negotiation and configuration occurs in real time at the moment when the remote unit first initiates a communication session with the base station. These negotiation and configuration events usually take place in a serialized format, meaning there is an initial sequence of events that occur between an initiating mobile device and a base station, followed by a similar sequence of events between the base station and a target mobile device. These sequence of events entail a process wherein each request or command from one device must first be responded to by the second device before other subsequent requests or commands take place between the devices. Furthermore, all such communication between the first mobile device and the base station must be completed before similar communications occur between the base station and the target mobile device.
In particular, packet mode capable user equipment request data sessions from their serving infrastructure nodes such as the base station by means of signaling negotiations. Essentially, a signaling channel has to be established and authenticated with the base station system in order for a service to be established between the mobile unit and the base. A certain amount of time delay is associated with the signaling from the initiating mobile unit, the authentication by the system and the negotiation of a certain quality of service. This time delay phenomena is further exaggerated when a first mobile unit attempts to communicate with a second mobile unit or paged target. In such an instance, the paged target or second mobile unit will go through the same set-up and negotiation procedure in order to establish a link with the base station system, thus resulting in a lengthy set-up time.
A reduction in the set-up time will result in quicker communications and ultimately a reduction in the amount of time for which a particular communication frequency is tied up. The importance of reducing this time can be quite dramatic depending on the mobile unit application. For instance, a dispatch unit that needs to communicate with multiple mobile units would benefit greatly from a reduced set-up time in reaching the targets. As such, there exists a need to provide a system and method to reduce the time and set-up procedures for communication between an initiating mobile unit and other target mobile units.
The invention relates to a system and method for use in wireless packet data mode communications, for enabling communication between a source device and one or more target devices by capturing in a control structure, one or more communication parameters during the set up of the source device and a base station. The set-up involves a series of interactive and sequenced communications between the source device and the base station. The invention involves the transmitting of the control structure to the one or more target devices and utilizing the control structure to contemporaneously configure the one or more target devices so that the target devices can communicate with the source device via the base station. One of the advantages of the invention is the reduction in set-up time for remote units.